1. Field of the Invention
The present invention relates generally to a mobile terminal, and in particular, to a built-in single band antenna device and an operating method thereof in a mobile terminal.
2. Description of the Related Art
In general, an antenna device in a mobile terminal includes a helical antenna protruding outside the terminal and a whip antenna. When the whip antenna is retracted into the interior of the terminal, the helical antenna operates and when the whip antenna is extended from the terminal, the whip antenna operates.
FIGS. 1A and 1B illustrate a conventional antenna for a mobile terminal. When a whip antenna 100 is contained inside a terminal 104 as shown in FIG. 1, an RF (Radio Frequency) signal is transmitted/received through a helical antenna 102 formed in an external protrusion portion 106. When the whip antenna 100 is pulled out as shown in FIG. 1B, the RF signal is transmitted/received through the whip antenna 100.
The protrusion of the helical antenna outside the terminal with the interworking structure of the conventional extendable whip antenna and the helical antenna impedes diverse designing of the terminal along the miniaturization trend and decreases portability. Besides, in case a user inadvertently drops the terminal from a certain height, the helical antenna is susceptible to breakage.
The protrusion of the helical antenna from one side of the terminal makes the configuration of terminal asymmetrical. The resulting asymmetry of a radiation pattern in a radio frequency band deteriorates directionality-related performance.